A Contact lens that delivers drugs

Reseachers of the University of Florida have developed soft contact lenses that contain tiny particles, which are filled with drugs. Such lenses would have significant advantages over eye drops.

People suffering from glaucoma or other eye diseases which could one day replace their eye drops with such drug-containing contact-lenses. They deliver the medication precisely when and where it is needed. The lenses have been presented at the American Chemical Society´s national meeting in New Orleans.

Millions of people all over the world suffer from eye diseases, such as glaucoma, cataracts and others. Besides surgery these diseases are often treated with drops containing powerful drugs. Some of this medication reaches its target, but most of it winds up in the body. “The negative drug side effects range up to possibly heart problems”, Anuj Chauhan said, a UF assistant professor of chemical engineering.

The researching team developed a technique to encapsulate a test drug in tiny “nanoparticles”. They mixed these particles into the same material used to make commercial contact lenses and fashioned large contact lenses with characteristics similar to manufactured ones.

The particles are so small, that they don´t scatter light. As a result of these circumstance, the particles didn´t cloud the finished lenses. And because the lenses would be suspended in the moist environment of the eye, the drug would seep out slowly. In laboratory tests, a test drug “Lidocaine”, a local anesthetic, diffused from the contact lenses into a surrounding solution in quantities appropriate for therapy fro about five days. The nanoparticles not only provide slow release, they also distribute the drug to the thin area sandwiched between the eye and the contact lens.

There is a long way to go and there still remain many obstacles, but this new method provides a real chance at having a method to provide sustained and controlled drug delivery to the eye.